[PATCH AUTOSEL 6.14 533/642] netdevsim: allow normal queue reset while down

Sasha Levin
2025-05-05T22:35:53Z

From: Jakub Kicinski <kuba@kernel.org>

[ Upstream commit 285b3f78eabd951e59e98f01f86abaaa6c76cd44 ]

Resetting queues while the device is down should be legal.
Allow it, test it. Ideally we'd test this with a real device
supporting devmem but I don't have access to such devices.

Reviewed-by: Mina Almasry <almasrymina@google.com>
Link: https://patch.msgid.link/20250206225638.1387810-5-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/netdevsim/netdev.c | 10 ++++------
tools/testing/selftests/net/nl_netdev.py | 18 +++++++++++++++++-
2 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/drivers/net/netdevsim/netdev.c b/drivers/net/netdevsim/netdev.c
index e4c0d77849b82..a41dc79e9c2e0 100644
--- a/drivers/net/netdevsim/netdev.c
+++ b/drivers/net/netdevsim/netdev.c
@@ -664,8 +664,11 @@ nsim_queue_mem_alloc(struct net_device *dev, void *per_queue_mem, int idx)
if (ns->rq_reset_mode > 3)
return -EINVAL;

- if (ns->rq_reset_mode == 1)
+ if (ns->rq_reset_mode == 1) {
+ if (!netif_running(ns->netdev))
+ return -ENETDOWN;
return nsim_create_page_pool(&qmem->pp, &ns->rq[idx]->napi);
+ }

qmem->rq = nsim_queue_alloc();
if (!qmem->rq)
@@ -773,11 +776,6 @@ nsim_qreset_write(struct file *file, const char __user *data,
return -EINVAL;

rtnl_lock();
- if (!netif_running(ns->netdev)) {
- ret = -ENETDOWN;
- goto exit_unlock;
- }
-
if (queue >= ns->netdev->real_num_rx_queues) {
ret = -EINVAL;
goto exit_unlock;
diff --git a/tools/testing/selftests/net/nl_netdev.py b/tools/testing/selftests/net/nl_netdev.py
index 93e8cb671c3d9..beaee5e4e2aab 100755
--- a/tools/testing/selftests/net/nl_netdev.py
+++ b/tools/testing/selftests/net/nl_netdev.py
@@ -35,6 +35,21 @@ def napi_list_check(nf) -> None:
comment=f"queue count after reset queue {q} mode {i}")

+def nsim_rxq_reset_down(nf) -> None:
+ """
+ Test that the queue API supports resetting a queue
+ while the interface is down. We should convert this
+ test to testing real HW once more devices support
+ queue API.
+ """
+ with NetdevSimDev(queue_count=4) as nsimdev:
+ nsim = nsimdev.nsims[0]
+
+ ip(f"link set dev {nsim.ifname} down")
+ for i in [0, 2, 3]:
+ nsim.dfs_write("queue_reset", f"1 {i}")
+
+
def page_pool_check(nf) -> None:
with NetdevSimDev() as nsimdev:
nsim = nsimdev.nsims[0]
@@ -106,7 +121,8 @@ def page_pool_check(nf) -> None:

def main() -> None:
nf = NetdevFamily()
- ksft_run([empty_check, lo_check, page_pool_check, napi_list_check],
+ ksft_run([empty_check, lo_check, page_pool_check, napi_list_check,
+ nsim_rxq_reset_down],
args=(nf, ))
ksft_exit()

--
2.39.5